This invention relates to fasteners and drivers for fasteners, and more particularly to combination fasteners that can be driven by more than one configuration of driver head and combination drivers that can drive more than one configuration of fastener head.
Combination drivers capable of engaging and driving more than one configuration of threaded fastener can be useful while assembling parts. For example, numerous prior art drivers combine a slotted-head and a cruciform-head, such as a Phillips-type screwdriver, onto a single shaft to enable the single, combination driver to engage both a screw having a single-slotted head and a screw having a Phillips-type head. Also, prior art combination drivers include configurations that mate with conventional hexagonal head fasteners, such as the combination driver disclosed in U.S. Pat. No. 4,367,664. Combination fasteners, such as hexagonal-head fasteners having a slot for a standard screw driver also are well-known.
For orthopedic or other surgeries in which threaded fasteners are affixed to part of a body, the fastener's head type and size are often recorded on an x-ray record of the body. Accordingly, in a subsequent surgery to remove or otherwise access the fasteners, the same x-ray record used for medical analysis identifies the proper type and size of driver to engage the fasteners. Sometimes, however, the subsequent surgery to remove or otherwise access the fasteners occurs without the use of the identifying information, such as when the information is not entered onto the original x-ray record or the original record is not available. Identifying the type and size of the fastener in order to choose the appropriate driver during surgery is otherwise difficult without open dissection because of the position of the fasteners in the body and because fluid may obscure the fastener.